Calculation of vibration–rotation spectra for rare gas–HCl complexes

Abstract

Calculations are described of spectra for the excitation of the bending and stretching vibrational–rotational energy levels in the van der Waals complexes of HCl with the rare gases Ne, Ar, Kr, and Xe. The calculations are performed using a basis set method, with distributed Gaussian functions being employed for the coordinate associated with the stretching of the rare gas atom. Intensities of combination and fundamental transitions for each of the low frequency modes are calculated for total angular momentum up to J=25. Surprisingly large intensities are predicted for transitions to states with multiple vibrations excited in the bending mode. Promising comparisons are obtained with infrared spectra measured recently for the complexes of HCl with Ne and Ar at low temperatures.